Yes, I feel you need to talk a little about yourself; talk about how your passion for chemistry developed, what influenced you pursuing your major, your background... :)
I came to my university knowing that I wanted to pursue a doctorate in chemistry, however I was unsure of what specialty I wished to pursue.
I entered the university knowing that I would end up pursuing a doctorate in Chemistry though I was not sure of the field that I would want to specialize.I wanted to then move to a post doctorate position, finally becoming a researching professor in my field
.... I think all these descriptions are not really necessary.I have grown a strong set of basic skills at my university and wish to learn and grow throughout my graduate career and well beyond.
I developed a many skills during my undergraduate and graduate studies.
I think you need to improve the presentation of your PS. Start with some experience that reflects how your passion developed. Then talk about how you pursued your passion. Talk about your research experience. Then tell them what your future goals are. Don't be too descriptive when telling just one idea. :)